Chain extended dendritic polyether

ABSTRACT

A chain extended dendritic polyether comprising a dendritic core polymer and a chain extension bonded to said core polymer, which chain extended dendritic polyether optionally is at least partially chain terminated and/or partially functionalised. The core polymer is a polyhydric dendritic polyether and the chain extension is obtained by addition of at least one alkylene oxide to at least one hydroxyl group in said core polymer.

This application is a §371 Application of International Application No.PCT/SE03/00117, filed on Jan. 22, 2003, claiming the priority of SwedishApplication No. 0200207-9, filed Jan. 25, 2002, the entire disclosuresof which are incorporated herein by reference in their entireties.

The present invention refers to a chain extended dendritic polyethercomprising a polyhydric dendritic core polymer and chain extensionbonded to said core polymer, which chain extended dendritic polyetheroptionally is at least partially chain terminated and/or functionalised.Said chain extension is obtained by addition of at least one alkyleneoxide. In a further aspect, the present invention refers to acomposition comprising the subject chain extended dendritic polyetherand in yet a further aspect to the use of the same.

Compounds with a highly branched, treelike, molecular structure havebeen known for a long time. Dendritic polymers belong to a group ofpolymers characterised by densely branched structures and a large numberof end groups. They are obtained by for instance polymerisation ofAB_(x) monomers, typically AB₂ monomers, giving branched structures withan exponential growth in both molecular weight and end groupfunctionality as a function of the degree of polymerisation. Polymersdesignated as dendritic, or sometimes hyperbranched, may to a certaindegree hold an asymmetry, yet maintaining the highly branched treelikestructure. Dendrimers generally are highly symmetric. Dendrimers can besaid to be monodisperse species of dendritic polymers. Dendriticpolymers normally consist called generations and the nucleus having oneor more reactive sites and a number of branching layers and, optionally,a layer of chain terminating molecules. The layers are usually calledgenerations and the branches dendrons, which are designations hereinused. It is well known that the globular structures obtained withdendritic polymers allow for excellent flow and processing properties athigh molecular weights. The exceptional concentration of reactive groupsallows for rapid curing in thermosetting applications and provide uniquepossibilities to customise properties in a wide range of differentend-uses.

Literature discussing various highly branched and dendritic moleculesand macromolecule include:

“Polybenzyl Type Polymers”, by Howard C. Haas et al published in J.Polymer Sci. vol. XV (1955) pp. 503–515, wherein non-randomlysubstituted highly branched benzyl type polymers are synthesized andanalysed.

“Strukturuntersuchungen an Sternmolekülen mit Glykogen als Kern”, byWalther Burchard et al published in Makromolekulare Chemie, 150 (1971)pp. 63–71, wherein the structure of molecules having treelike amylosechains and a glycogen core are disclosed.

“Statistical Mechanism of Random Coil Networks”and “Elasticity and ChainDimensions in Gaussian Networks”, by William W. Graessley published inMacromolecules, vol. 8 no. 2 (1975) pp. 186–190 and vol. 8 no. 6 (1975)pp 865–868, wherein molecules comprising tri and tetrafunctional centralcores (initiators) and concentrically treelike (dendritic) branches aredisclosed. The term micronetworks is introduced to describe thesemolecules.

“Static and Dynamic Scattering Behavior of Regularly Branched Chains: AModel of Soft-Sphere Microgels”, by Walther Burchard et al published inJ. Polymer Sci. Polym. Phys. Ed., vol. 20 (1982) pp. 157–171, wherein isdisclosed, among other models, the theory behind a molecular modelcomprising a trifunctional core being symmetrically branched wherebycontinued branch replication yields increased branch multiplicity and aincreased number of terminal groups.

Various dendritic materials have during the last one or two decadesattracted general attention. Patents, patent applications and otherworks issued or published during the last decades are summarised by forinstance H. Galina et al in Polymery; English translation in Int. Polym.Sci. Tech., 1995, 22, 70. The state of the art is excellently compiledin for instance “Dendritic Molecules Concepts Syntheses Perspective” byG. R. Newkome, C. N. Moorefield and F. Vögtle—VCH VerlagsgesellschaftmbH, 1996.

A number of patents and patent applications disclosing various dendriticpolymers and processes for synthesis thereof have for various types ofproducts been issued or published and include EP 0 115 771, SE 468 771,WO 93/18075, EP 0 575 596, SE 503 342, US 5,561,214, WO 00/56802.

EP 0 115 771 claims a dense star polymer having at least threesymmetrical core branches, each core branch having at least on terminalgroup, and a ratio terminal groups to core branches being greater than2:1. The properties of claimed polymer is specified through acomparative relation to an unspecified star polymer. EP 0 115 771 alsorelates to a process, which process substantially also is disclosed inUS 4,410,688, for synthesis of a symmetrical dense start polymer. Theprocess teaches a repeated and alternately addition of alkyl acrylateand alkylene diamine to a core consisting of ammonia.

SE 468 771 discloses a dendritic macromolecule substantially built upfrom polyester units and a process for synthesis of said macromolecule.The macromolecule is composed of an initiator, having at least onhydroxyl group, to which initiator at least one branching generationcomprising at least one chain extender, having at least one carboxylgroup and at least two hydroxyl groups, is added. The macromolecule isoptionally chain terminated. The process for synthesis of saidmacromolecule teaches a co-esterification of the initiator and the chainextender, optionally followed by a chain termination. The process yieldsinexpensive polydisperse dendritic macromolecules.

WO 93/18075 teaches a hyperbranched polymer having at least six terminalhydroxyl or carboxyl groups and a process for its synthesis. Thehyperbranched polymer is synthesized by repeated and alternatelyaddition of a compound having at least one anhydride group followed by acompound having at least one epoxide group to a core having at least onehydroxl group.

EP 0 575 596 discloses a dendritic macromolecule comprising a corehaving 1–10 functional groups and branches synthesized from vinylcyanide units as well as a process for synthesis thereof. The processinvolves three repeated steps beginning with reaction between the coreand monomeric vinyl cyanide units followed by reduction of incorporatednitrile groups to amine groups. In a third step said amine groups arereacted with monomeric vinyl cyanide units.

SE 503 342 discloses a dendritic macromolecule of polyester type and aprocess for synthesis of said macromolecule. The macromoleculesubstantially is composed of a core, having at least one epoxide group,to which core at least one branching generation comprising at least onechain extender, having at least three reactive functions of which atleast one is a carboxyl or epoxide group and at least one is a hydroxylgroup, is added. The macromolecule is optionally chain terminated. Theprocess teaches self condensation of the chain extender moleculesyielding a dendron (a core branch), which dendron in a second step isadded to the core. The process also comprises an optional further chainextension by addition of spacing or branching chain extenders and/or anoptional chain termination. The process yields inexpensive polydispersedendritic macromolecules.

WO 00/56802 discloses dendritic polyethers obtained by ring openingpolymerisation of oxetanes, optionally in the presence of a coremolecule. The polyethers are optionally further processed such as chainextended, chain terminated and/or functionalised by reaction withcompounds such as hydroxyfunctional carboxylic acids, lactones,carboxylic acids, haloperoxyacids, isocyanates, allylhalides andepihalohydrins.

Dendritic polyethers made by ring opening polymerisation have attractedsome interest recently. Both dendritic structures made from glycidol and3-ethyl-3-hydroxmethyl oxetane have been studied and published by interalia E. J. Vandenberg, Pol. Sci., Part A: Polym. Chem., 1989, 27, 3113,A. Sunder et.al., Macromolecules, 1999, 32, 4240, and H. Magnussonet.al. Macromol. Rapid Commun., 1999, 20, 453–457.

Dendritic polyethers obtained by ring opening polymerisation offer arapid process for obtaining dendritic structures. Dendritic polyethersare furthermore hydrolytically stable, which is of interest forapplications wherein an aqueous and/or alkaline environment is employed.

It is of particular interest to study dendritic polyethers made by ringopening polymerisation of 3-ethyl-3-hydroxymethyl oxetane(trimethylolpropane oxetane, TMPO), since the monomer is non-toxic andhence environmentally friendly. The TMPO monomer is, furthermore, onlypossible to polymerise under cationic conditions, which allows thehydroxyl functionality to be modified under alkaline conditions prior topolymerisation. Said modified product can then be used as co-monomerwith neat TMPO and specific functionalities can thereby be incorporatedin the inherent dendritic polymer backbone. Dendritic polymers made fromTMPO offer interesting physical properties such as a glasstransitiontemperature (Tg) in the range of 40° C., yet low melt viscosity atelevated temperatures. They are also as previously disclosedhydrolytically stable and can be used in strongly alkaline environments.

It has now been found that it is possible, in spite of the highfunctionality and molecular weight, to use hydroxyfunctional dendriticpolyethers as core molecules which through anionic ring opening arelinearly extended with cyclic ethers of oxirane type, whereby chainextended dendritic polyethers with terminal hydroxyl groups and narrowmolecular weight distribution are obtained.

The present invention accordingly refers to novel chain extendeddendritic polyether comprising a dendritic core polymer and asubstantially linear chain extension bonded to said core polymer. Thechain extended dendritic polyether may optionally be at least partiallychain terminated and/or functionalised. The core polymer is a polyhydricdendritic polyether and the chain extension is obtained by addition ofat least one alkylene oxide to at least one hydroxyl group in said corepolymer. The preferred molar ration said core polymer to said alkyleneoxide is between 1:1 to 1:100, such as between 1:3 and 1:50. The noveldendritic polymer of the present invention useful as a product per se oras component, raw material, in the manufacture of a large number ofresinous and polymeric products.

The chain extended dendritic polyether according to the presentinvention has exceptionally low viscosity with regard to its molecularweight. Obtained viscosity range is regarded as being the lowest valuesreported for any polydisperse dendritic polymer at a given molecularweight and hydroxyl functionality. The chain extended dendriticpolyether according to the present invention has, furthermore, aninherently flexible backbone promoting good flexibility and adhesion tocoatings as well as thermoset resins. The high end group functionalityprovides, at the same time excellent film hardness and modulus retentionto coatings and thermoset resins. The chain extended dendritic polyetheraccording to the present invention provides a unique amphiphiliccharacter. Obtained linear alkylene oxide chains will, when using forinstance ethylene oxide as chain extending monomer, since they arehydrophilic provide inherent surfactant and stabilising properties. Thehigh end group functionality of the chain extended dendritic polyethersaccording to the invention, allows for chain stoppers of hydrophobicnature, such as aliphatic mono isocyanates or carboxlic acids, to beused to provide the dendritic polyether with an amphiphilic nature. Theamphiphilic products obtained have unexpectedly been found to beexceptionally effective as dispersing agents for pigments and asdispersing resins for alkyds, polyesters, polyurethanes and polymerdispersions obtained by emulsion polymerisation. Dispersing products areobtained when unsaturated carboxylic acids, such as sunflower fattyacid, tall oil fatty acid or linseed fatty acid, are used, whichdispersing products when mixed with dryers will contribute tocrosslinking of formed films. Coatings with good rheological propertiesand excellent final film properties can hence be obtained without theuse of solvents, coalescent agents and/or conventional surfactants.Radiation curing polymers with high functionality, high molecular weightand low viscosity are obtained when unsaturated carboxylic acids, suchas acrylic and maleic acids, are used.

The alkylene oxide providing the substantially linear chain extension isin preferred embodiments of the present invention ethylene oxide,propylene oxide, 1,3-butylene oxide, 2,4-butylene oxide, cyclohexeneoxide, butadiene monoxide, phenylethylene oxide or a mixture of two ormore of said alkylene oxides.

The polyhydric dendritic polyether, used as core polymer according tothe present invention, is preferably obtained by ring opening additionof at least on oxetane to a di, tri or polyhydric core molecule at amolar ratio yielding a polyhydric dendritic polyether comprising a coremolecule and at least one branching generation bonded to at least onehydroxyl group in said di, tri or polydydric core molecule. The di, trior polyhydric core molecule is in preferred embodiments of thepolyhydric dendritic polyether a di, tri or polyhydric alcohol or areaction product between at least one alyklene oxide, such as ethyleneoxide, propylene oxide, 1,3-butylene oxide, 2,4-butylene oxide,cyclohexene oxide, butadiene monoxide and/or phenylethylene oxide, and adi, tri or polyhydric alcohol. Said di, tri or polyhydric alcohol issuitably selected from the group consisting of 1,ω-diols,5-hydroxy-1,3-dioxanes, 5-hydroxyalkyl-1,3-dioxanes,5-hydroxyalkyl-1,3-dioxanes, 5,5-di(hydroxyalkyl)-1,3-dioxanes,2-alkyl-1,3-propanediols, 2,2-dialkyl-1,3-propanediols,2-hydroxy-1,3-propanediols, 2-hydroxy-2-alkyl-1,3-propanediols,2-hydroxyalkyl-2-alkyl-1,3-propanediols,2,2-di(hydroxyalkyl)1,3-propanediols and dimers, trimers or polymers ofsaid di, tri or polyhydric alcohols. Alkyl is here preferably C₁–C₂₄,such as C₁–C₁₂ or C₁–C₈ alkanyl or alkenyl.

Various embodiments of the polyhydric dendritic polyether includeespecially preferred embodiments wherein the di, tri or polyhydric coremolecule is 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,1,6-cyclohexanedimethanol, 5,5-dihydroxymethyl-1,3-dioxane,2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol,2-ethyl-2-butyl-1,3-propanediol, neopentyl glycol, dimethylolpropane,1,1-dimethylolcyclohexane, glycerol, trimethylolethane,trimethylolpropane, diglycerol, distrimethyloethane,ditrimethylolpropane, pentaerythritol, dipentaerythritol,anhydroenneaphepitol, sorbitol, mannitol or a reaction between apreviously disclosed alkylene oxide and a herein disclosed alcohol.

The oxetane providing said at least one branching generation ispreferably and advantageously a 3-alkyl-3-(hydroxyalkyl)oxetane, a3,3-di(hydroxyalkyl)oxetane, a 3-alkyl-3-(hydroxy-alkoxy)oxetane, a3-alkyl-3-(hydroxyalkoxyalkyl)oxetane or a dimer, trimer or polymer of a3-alkyl-3-(hydroxyalkyl)oxetane, a 3,3-di(hydroxyalkyl)oxetane, a3-alkyl-3-(hydroxyalkoxy)-oxetane or a3alkyl-3-(hydroxyalkoxyalkyl)oxetane. Alkyl is her preferably _(C)₁–C₂₄, such as C₁–C₁₂ or C₁–C₈ alkanyl or alkenyl and alkoxy comprisespreferably 1–50, such as 2–20, alkoxy units derived from at least onealkylene oxide, such as ethylene oxide, propylene oxide, 1,3-butyleneoxide, 2,4-butylene oxide, cyclohexene oxide, butadiene monoxide,phenylethylene oxide or a mixture of two or more of said alkyleneoxides. Said oxetane is most preferably an oxetane of trimethylolethane,trimethylolpropane, pentearythritol, ditrimethylolethane,ditrimethylolpropane or dipentaerythritol, such as3-methyl-3-(hydroxy-methyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetaneand/or 3,3-di(hydroxymethyl)oxetane.

The chain extended dendritic polyether of the present invention issuitably at least partially chain terminated by addition to said chainextension and/or said core polymer of at least one aliphatic or aromaticsaturated or unsaturated carboxylic acid or a corresponding anhydride orhalide, at least one hydroxyfunctional carboxylic acid, such as2,2-bis(hydroxymethyl)propanoic acid, 2,2-bis(hydroxymethyl)butanoicacid, 2,2-bis(hydroxmethyl)pentanoic acid, 2,3-dihydroxy-propanoic acid,hydroxpentanoic acid, hydroxypropanoic acid and/or2,2-dimethyl-3-hydroxypropanoic acid, at least one lactone, such asβ-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone and/orζ-enantholactone, at least one aliphatic or aromatic mono ordiisocyanate, such as toluene-2,4-diisocyanate,toluene-2,6-diisocyanate, hexamethylene diisocyanate and/or isophoronediisocyanate, at least one epoxidised saturated or unsaturated alcohol,such as a C₅–C₂₄ alkanol or alkenol, at least one allyl or vinylether,at least one thiol, at least one glycidyl ether, and/or at least onesulphonate or phosphate, and/or is at least partially functionalised byreaction with at least haloperoxy acid or anhydride, such asperoxyformic acid, peroxyacetic acid, peroxybenzoic acid,m-chloroperoxybenzoic acid and/or trifluoroperoxyacetic acid, at leastone allyhalide, such as allybromode and/or allychloride, and/or at leastone epihalohydrin, such as epichlorohydrin or epidbromohydrin.

Said at least one aliphatic or aromatic carboxylic acid is suitableacetic acid, propionic acid, butyric acid, valeric acid, isobutyricacid, trimethylacetic acid, 2-ethylhexanoic acid, nonanoic acid,isononanoic acid, heptanoic acid, caproic acid, caprylic acid, capricacid, benzoic acid, para-tert.butylbenzoic acid, pelargonic acid, lauricacid, myristic acid, palmitic acid, stearic acid, isotearic acid,behenic acid, lignoceric acid, cerotic acid, montanoic acid, abieticacid, sorbinic acid, oleic acid, ricinoleic acid, linoleic acid,linolenic acid, erucic acid, soybean fatty acid, linseed fatty acid,dehydrated castor fatty acid, tall oil fatty acid, tung oil fatty acid,sunflower fatty acid, safflower fatty acid, o-phthalic acid, isophthalicacid, terephtalic acid, azeleic acid, adipic acid and/or trimelleticacid or, where applicable, a to a said acid corresponding anyhydride.

Said at least one carboxylic acid is furthermore preferably acrylicacid, methacrylic acid, crotonic acid, isocrotonic acid or a to a saidacid corresponding anhydride or halide, and/or maleic anhydride orfumaric acid. Said at least partial chain termination confers, whenperformed by addition of at least one of said preferred acids,properties possible to utilise in for instance radiation curing coatingsand inks.

The present invention refers in a further aspect to a compositioncomprising the chain extended dendritic polyether disclosed above in anamount of at least 0.1%, such as 0.5–80%, 0.5–50% or 1–25%, by weight.

Various embodiments of the chain extended dendritic polyether of thepresent invention are suitably and advantageously used as or utilised inpreparation of air drying allyd resins, 1-and 2-component polyurethanecoatings and adhesives, saturated and unsaturated polyesters, tougheningagents for thermosetting resins, such as epoxy resins, unsaturatedpolyester, vinyl esters, polyurethanes, maleimides, cyanate esters,phenolics, uera-formaldehyde resins and melamine-formaldehyde resins aswell as composites made therefrom, pigment dispersion agents forsolvent-free, solventborne and waterborne coatings, water dispersibleresins for alkyd emulsions, acrylic dispersions and polyurethanedispersions, dispersing polymers or resins, such as reactive polymericsurfactants, for non-amphifilic alkyds, polyesters, polyethers andpolyurethanes, processing aids for polyolefines and thermoplastics, suchas polycarbonates, polyesters, polyamides, polyimides and polyurethanes,concrete admixtures imparting for instance fluidity to hydrauliccompositions, such as cement pastes, mortars and concretes, and/orradiation curing coatings, printing inks and adhesives.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative and not limitative ofthe remainder of the disclosure in any way whatsoever. These and otherobjects and the attendant advantages will be more fully understood fromthe following detailed description, taken in conjunction with appendedembodiment Examples 1–19 illustrating:

Examples 1 and 2: Preparation second and third generation dendriticpolyethers used in

Example 3–6 as core polymers.

Examples 3 and 4: Preparation of chain extended dendritic polyethers inaccordance with embodiments of the present invention. The product ofExample 1 is used as core polymer and ethylene oxide as chain extensionmonomer.

Examples 5 and 6: Preparation of chain extended dendritic polyethers inaccordance with embodiments of the present invention. The product ofExample 2 is used as core polymer and ethylene oxide as chain extensionmonomer.

Example 7 and 8: Chain termination, in accordance with embodiments ofthe present invention, of the chain extended dendritic polyethers ofExamples 3 and 5. Acrylic acid is used as chain termination monomer.

Example 9: Chain termination, in accordance with an embodiment of thepresent invention, of the chain extended dendritic polyether of Example4. Sunflower fatty acid is used as chain termination monomer.

Example 10 and 11: Evaluation in radiation curing coatings of theproducts obtained in Examples 7 and 8.

Example 12: Evaluation as toughener in anhydride cured epoxy resin ofthe products obtained in Example 5.

Example 13–18: Preparation of waterborne systems using the productobtained in Example 9.

Example 19: Evaluation of waterborne systems obtained in Examples 14–18.

Example 1

7.28 kg of ethoxylated pentaerythritol (Polyol PP50^(υ), PerstorpSpecialy Chemicals AB) and 71.7 g of BF₃ ethyl etherate were charged toa steel reactor equipped with stirrer, oil heating, water cooling,nitrogen inlet and cooler. The mixture was heated to 110° C. Forcedcooling was imposed to the reactor and addition of 28.55 kg of a3-ethyl-3-(hydroxymethyl)oxetane (TMPO) commenced at a feeding rate of0.82 kgm⁻¹. The reaction was exothermic and the exotherm continued for afurther 20 minutes after completed feeding of TMPO and excessive coolingwas required. The reaction was then allowed to continue at 110° C. for afurther 4 hours after which 125 g of aqueous NaOH (41%) was added tostop the living character of the polymer. The reaction mixture wasstirred for 20 minutes at 110° C. and full vacuum was then applied toremove any residual monomer and water originating from the aqueous base.

Obtained polyhydric dendritic polyether of two generations exhibitedfollowing properties:

Hydroxyl value, mg KOH/g: 518 Molecular weight, (GPC) g/mole: 1450Nominal molecular weight, (GPC) g/mole: 1088 Polydispersity index: 1.33

Example 2

3.64 kg of ethoxylated pentaerythritol (Polyol PP50⁹⁸, PerstorpSpecialty Chemicals AB) and 73.7 g of BF₃ ethyl etherate were charged toa steel reactor equipped with stirrer, oil heating, water cooling,nitrogen inlet and cooler. The mixture was heated to 110° C. Forcedcooling was imposed to the reactor and addition of 33.2 kg of a3-ethyl-3-(hydroxymethyl)oxetane (TMPO) commenced at a feeding rate of0.82 kgm⁻¹. The reaction was exothermic and the exotherm continued for afurther 20 minutes after completed feeding of TMPO and excessive coolingwas required. The reaction was then allowed to continue at 110° C. for afurther 4 hours after which 405 g of aqueous NaOH (41%) was added tostop the living character of the polymer. The reaction mixture wasstirred for 20 minutes at 110° C. and full vacuum was then applied toremove any residual monomer and water originating from the aqueous base.

Obtained polyhydric dendritic polyether of three generations exhibitedfollowing properties:

Hydroxyl value, mg KOH/g: 496 Molecular weight, (GPC) g/mole: 3006Nominal molecular weight, (GPC) g/mole: 2362 Polydispersity index: 1.27

Example 3

35.5 kg of the polyhydric dendritic polyether obtained in Example 1 washeated to 80° C. and an aqueous solution of KOH was charged in an amountcorresponding to 357 g of neat KOH. The reaction mixture was stirred atsaid temperature for 1 hour, after which the alcoholate of the productobtained in Example 1 was considered to have formed. Full vacuum wasthen applied and the temperature was gradually increased to 110° C. toremove any water present in the alcoholate mixture. 28.8 kg of ethyleneoxide was now under pressure and nitrogen atmosphere charged to thereaction mixture during 1.5 hour and the temperature was kept at110–120° C. The reaction was allowed to continue at 110° C. for afurther 3 hours after completed feeding of ethylene oxide. The reactionproduct was then cooled to 80° C. and sulphuric acid was added instoichiometric amounts to previously charged KOH. K₂SO₄precipitated fromthe solution and was removed by filtration, after which the finalproduct was recovered.

Obtained chain extended dendritic polyether exhibited followingproperties:

Hydroxyl value, mg KOH/g: 291 Average hydroxyl functionality, eq: 14.1Peak molecular weight (GPC), g/mole: 2723 Molecular weight (GPC),g/mole: 2575 Nominal molecular weight (GPC), g/mole: 2033 Polydispersityindex (PDI): 1.27 Viscosity (25° C., Brookfield), mPas: 9200Non-volatile content, % by weight: 99.5

Example 4

Example 3 was repeated with the difference that 86.5 kg of ethyleneoxide was charged instead of 28.8 kg and that the feeding time was 3 hrsinstead of 1.5 hr.

Obtained chain extended dendritic polyether exhibited followingproperties:

Hydroxyl value, mg KOH/g: 150 Average hydroxyl functionality, eq: 10.8Peak molecular weight (GPC), g/mole: 4052 Molecular weight (GPC),g/mole: 4181 Nominal molecular weight (GPC), g/mole: 3153 Polydispersityindex: 1.33 Viscosity (25° C., Brookfield), mPas: 2200 Non-volatilecontent, % by weight: 99.5

Example 5

36.5 kg of the polyhydric dendritic polyether obtained in Example 2 wascharged to a reactor and heated to 80° C. and an aqueous solution of KOHwas charged in an amount corresponding to 450 g of neat KOH. Thereaction mixture was stirred at said temperature for 1 hour, after whichthe alcoholate of the product obtained in Example 1 was considered tohave formed. Full vacuum was then applied and the temperature wasgradually increased to 110° C. to remove any water present in thealcoholate mixture. 28.8 kg of ethylene oxide was now under pressure andnitrogen atmosphere charged to the reaction mixture during 1.5 hour andthe temperature was kept at 110–120° C. The reaction was allowed tocontinue at 110° C. for a further 3 hours after completed feeding ofethylene oxide. The reaction product was then cooled to 80° C. andsulphuric acid was added in stoichiometric amounts to previously chargedKOH. K₂SO₄ precipitated from the solution and was removed by filtration,whereafter the final product was recovered.

Obtained chain extended dendritic polyether exhibited followingproperties:

Hydroxyl value, mg KOH/g: 289 Average hydroxyl functionality, eq: 32.2Peak molecular weight (GPC), g/mole: 6362 Molecular weight (GPC),g/mole: 5204 Nominal molecular weight (GPC), g/mole: 2690 Polydispersityindex: 1.93 Viscosity (25° C., Brookfield), mPas: 22000 Non-volatilecontent, % by weight: 99.5

Example 6

Example 5 was repeated with the difference that 86.5 kg of ethyleneoxide was charged instead of 28.8 kg and that the feeding time was 3 hrsinstead of 1.5 hr.

Obtained chain extended dendritic polyether exhibited followingproperties:

Hydroxyl value, mg KOH/g: 149 Average hydroxyl functionality, eq: 18.6Peak molecular weight (GPC), g/mole: 7001 Molecular weight (GPC),g/mole: 6045 Nominal molecular weight (GPC), g/mole: 2607 Polydispersityindex: 2.32 Non-volatile content, % by weight: 99.5

Example 7

80.0 g of the chain extended dendritic polyether according to Example 2,32.1 g of acrylic acid (10%) by weight in excess to the stoichiometricratio) and 115 ml of toluene were at room temperature charged to areactor. The temperature was raised to 55° C. and 1500 ppm of4-methoxyphenol and 300 ppm of nitrobenzene were added. 1.1 g of methansulphonic acid was added when a clear solution was obtained. Thetemperature was now slowly raised to 110° C. and maintained to reflux.Air was allowed to bubble through the reaction mixture to avoidgelation. The acid value was after 7 hours 62 mg KOH/g and the reactionwas stopped. The reaction mixture was cooled to room temperature and theproduct filtered through a glass filtre. The reaction mixture wasneutralised to pH 7 with a 4% aqueous solution of NaOH. Separationbetween the aqueous phase and the organic phase occurred almostinstantaneously and the organic phase was washed 3 times with water(product:toluene/water=2:1). Remaining toluene was finally vaporised at40° C. and <10 mm Hg for 1 hour and the final product was recovered.

Obtained chain terminated chain extended dendritic polyether (chainextended dendritic polyether acrylate) exhibited following properties:

Final acid value, mg KOH/g: 2.5 Acrylate concentration, mmole/g: 3.2Peak molecular weight (GPC), g/mole: 4947 Molecular weight (GPC),g/mole: 4125 Nominal molecular weight (GPC), g/mole: 2610 Polydispersityindex: 1.58 Viscosity (25° C., 30 s⁻¹, Cone and Plate), mPas: 1100Non-volatile content, % by weight: 95.6

Example 8

Example 7 was repeated with the difference that the chain extendeddendritic polyether of Example 5 was used instead of the chain extendeddendritic polyether of Example 3.

Obtained chain terminated chain extended dendritic polyether (chainextended dendritic polyether acrylate) exhibited following properties:

Final acid value, mg KOH/g: 4.2 Acrylate concentration, mmole/g: 4.7Peak molecular weight (GPC), g/mole: 6783 Molecular weight (GPC),g/mole: 6826 Nominal molecular weight (GPC), g/mole: 3387 Polydispersityindex): 2.01 Viscosity (25° C., 30 s⁻¹, Cone and Plate), mPas: 2300Non-volatile content, % by weight: 97

Example 9

90.0 g of sunflower fatty acid was charged to a reactor equipped withstirrer, water removal trap of Dean-Stark type, cooler, temperaturecontrol, electric heater and nitrogen purge. The fatty acid was during 1hour heated to 80° C. 200 g of the chain extended dendritic polyether ofExample 4, 2.9 g of benzoic acid and 21.0 g of xylene were charged tothe heated fatty acid. The reaction mixture was now during 1 hour heatedto 175° C. at which temperature reflux commenced. The reaction wasallowed to continue for a further 12 hours. The temperature wasgradually increased, to maintain good reflux, until a final reactiontemperature of 195° C. was reached. Full vacuum was applied, when thereaction mixture had reached an acid value of approx. 7 mg KOH/g, toremove any residual solvent from the reaction mixture. The reactionmixture was then cooled to 50° C. and a filtering aid (celite) wasadded. Finally, the reaction mixture was passed through a pressurisedfilter and the final product was obtained.

Obtained chain terminated chain extended dendritic polyether (chainextended dendritic polyether alkyd) exhibited following properties:

Final acid value, mg KOH/g: 6.6 Hydroxyl value, mg KOH/g: 56 Molecularweight (GPC), g/mole: 7667 Nominal molecular weight (GPC), g/mole: 3324Polydispersity index): 2.31 Viscosity (Brookfield, 23° C.), mPas: 2570Non-volatile content, % by weight: 99.5

Example 10

The chain extended dendritic polyether acrylates obtained in Examples 7and 8 were mixed with 4% by weight of Irgacure²⁰⁰ 500 (photoinitiator,CIBA, Switzerland) and evaluated as clear coatings. The coatings wereproduced by the K-bar 12 μm on metal plates and passed 6 times under a80 W/cm mercury bulb lamp in a Wallace Knight Unit. Obtained curedcoatings were characterised by pendulum hardness (König pendulum),pencil hardness and Erichsen flexibility. Surface conversion of thedouble bonds was monitored by FTIR attenuated reflectance (NicoletProtégé) by monitoring the decrease of the double bond absorbency at 810cm⁻¹ and by using the carbonyl peak at 1715 cm⁻¹ as internal reference.

Crosscut test of coatings cured under the same conditions was done oncorona treated polyethylene in order to evaluate the adhesion and rankedas follows:

5: Intact 4 3 2 1 0: Bad

A comparison with a tetrafunctional amine modified polyether(Reference), characterised by a molecular weight of 1000 g/mole and aviscosity of 3 Pa.s at room temperature, was furthermore made. 4–7 timeshigher molecular weights at lower or similar viscosity and similaracrylate concentrations (approx. 4.0 mmole/g) were obtained withproducts according to the present invention compared with the referenceacrylate. Similar or higher flexibility, higher pendulum hardness,similar or higher chemical resistance and improved adhesion onpolyethylene were obtained with products according to Examples 7 and 8compared to the Reference.

The result of the evaluation is given in Table 1 below.

Example 11

The chain extended dendritic polyether acrylates obtained in Examples 7and 8 and the reference mentioned in Example 10 were mixed with analkoxylated pentaerythritol acrylate (Ebercryl^(®) 40, UCB Chemicals,Belgium) at a weight ratio 50:50. The formulations were cured with 2%Irgacure^(®)500 (photoinitiator, CIBA, Switzerland) and evaluated, at afilmthickness of 12 μm, as in Example 10.

Higher chemical resistance and improved adhesion is obtained withproducts according to Examples 7 and 8 compared to the Reference.

The result of the evaluation is given in Table 2 below.

Example 12

The chain extended dendritic polyether according to example 5 wasevaluated as toughener in an anhydride cured epoxy resin.

5 parts and 10 parts, respectively, of the chain extended dendriticpolyether according to Example 5 were at room temperature added to andmixed into 100 parts of a bisphenol-A type of epoxy (LY556, Vantico,Switzerland). Opaque solutions were obtained. 90 parts of an anhydridehardener (HY917, Vantico, Switzerland) and 1 part of an imidazoleaccelerator (DY070, Vantico, Switzerland) were then mixed with theopaque mixtures and the mixtures became fully transparent.

A reference was also prepared in the same manner as above, with thedifference that the chain extended dendritic polyether according toExample 5 was excluded.

The mixtures were subsequently poured into steel moulds with dimensionsaccording to the required specimen size for tensile testing and fracturetoughness evaluation. The filled moulds were first degassed in a vacuumoven to remove entrapped air and then cured according to the followingcuring schedule:

RT=>1.5° C./min=>80° C.=>4hrs at 80° C.=>1.5° C./min=>140° C.=>6hrs at140° C.=>−0.3° C./m=>RT

The cured specimens were free of defects when demoulded and fullytransparent. The cured specimens were then machined to dumb bell shapeaccording to standards for evaluation of tensile properties. Fracturetouchness was also evaluated with specimens machined into the shaperequired for the compact tension test.

Mechanical properties obtained with specimens comprising the chainextended dendritic polyether according to Example 5 and the Referenceare given in Table 3 below.

Example 13

The product of Example 9 was used to prepare a self emulsifyingwaterborne alkyd emulsion having following composition:

1. Product according to Example 9:  40 parts 2. Cobalt drier (Servosyn ®WED, 8% Co)*: 0.3 parts 3. Zirconium drier (Servosyn ® WED, 12% Zr)*:0.9 parts 4. Distilled water:  60 parts *Servo Delden B.V., TheNetherlands.

Components 1–3 were mixed by stirring and water was subsequently added.The pH was adjusted to 7 by addition of an aqueous dimethylamino ethanosolution (10%). A translucent emulsion was obtained. The emulsion wasafter 5 days at 40° C. still stable.

Obtained product exhibited following characteristics:

Solid content, % by weight: 41 Viscosity (23° C., 0 s⁻¹, Cone andPlate), Pa · s: 2.1 Volatile organic content (VOC), %: 0

Example 14

The alkyd emulsion prepared in Example 13 was used as a dispersingmedium for pigments. A high concentrated pigment paste was prepared byadding, during 20 minutes in a high speed dissolver at 2000 rpm, 70 g ofTiO₂ (Kronos^(®)2310) to 30 g of the alkyd emulsion obtained in Example13. The pigment paste was after 5 days at 40° C. still stable.

Obtained product exhibited following characteristics:

Pigment:resin, weight ratio: 5.8:1 Solid content, % by weight: 82Viscosity (23° C., 0 s⁻¹, Cone and Plate), Pa · s: 110 Viscosity (23°C., 500 s⁻¹, Cone and Plate), Pa · s: 3.5

Example 15

An alkyd/acrylic hybrid emulsion was prepared by mixing, during 20minutes, 30 parts of the product obtained in Example 13 with 70 parts ofan acrylic dispersion (Mowilith^(®) LDM 7451, Perstorp Clariant AB)having a solid content of 47%). Additives or coalescent agents were notused to prepare the hybrid system. The hybrid system was after 5 days at40° C. still stable.

Obtained product exhibited following characteristics:

Solid content, % by weight: 44.9 Volatile organic content (VOC), % 0Viscosity (23° C., 0 s⁻¹, Cone and Plate), Pa · s: 10 Viscosity (23° C.,500 s⁻¹, Cone and Plate), Pa · s: 0.3

Example 16

A waterborne paint formulation based on the alkyd/acrylic hybridemulsion of Example 15 and the pigment paste of Example 14 was preparedby slowly addding 60 g of said pigment paste to 90 g of saidalkyd/acrylic hyrbrid emulsion. Additives or coalescent agents were notused to prepare the hybrid system. The hybrid emulsion was after 5 daysat 40° C. still stable.

Obtained product exhibited following characteristics:

Solid content, % by weight: 59 Pigment:resin, weight ratio: 1:1.12Viscosity (23° C., 0 s⁻¹, Cone and Plate), Pa · s: 14 Viscosity (23° C.,500 s⁻¹, Cone and Plate), Pa · s: 0.55 Volatile organic content (VOC),%: 0

Example 17

The product of Example 9 was used to water disperse an alkyd resinintended for solvent borne systems and thus not giving a stable emulsionwhen water dispersed.

A 75% oil length alkyd, based on tall oil fatty acid andpentaerythritol, having a nominal molecular weight 4793 g/mole andhydroxyl value of 36 mg KOH/g was under stirring mixed with the productof Example 9 at a weight ratio 2:1. A cloudy highly viscous mixture wasobtained. The same dryers as in Example 13 were subsequently addedfollowed by addition of distilled water to a solid content of 50%.Obtained mixture was now stirred for 20 minutes resulting a stable milkyemulsion. The emulsion was after 5 days at 40° C. still stable.

Obtained product exhibited following characteristics:

Solid content, % by weight: 50 Viscosity (23° C., 0 s⁻¹, Cone andPlate)*, Pa · s 15 Viscosity (23° C., 500 s⁻¹)*, Pa · s: 0.55 Volatileorganic content (VOC), %: 0

The viscosity (s⁻¹, Cone and Plate) as a function of shear rate is givenis Graph 1 below.

Example 18

A waterborne paint formulation based on the alkyd emulsion of Example 17and the pigment paste prepared of Example 14 was prepared by slowlyadding 60 g of said pigment paste to 90 g of said alkyd emulsion. Thepaint was after 5 days at 40° C. still stable.

Obtained product exhibited following characteristics:

Solid content, % by weight: 62.8 Pigment:resin, weight ratio: 1:1.24Viscosity (23° C., 0 s⁻¹, Cone and Plate), Pa · s: 20 Viscosity (23° C.,500 s⁻¹, Cone and Plate), Pa · s: 1.2 Volatile organic content (VOC), %:0

Example 19

100 μm wet films from the formulations of Examples 14–18 were coated onglass panels and dried at 23±2° C. and 55±5% relative humidity. Theacrylic dispersion (Mowilith^(®) LDM 7451, Perstorp Clariant AB) ofExample 15 was used as Reference. The hardness was recorded using aKönig pendulum and expressed as König seconds.

The result is given in Table 4 below.

TABLE 1 Example 7 Example 8 Reference Pendulum hardness, König secs.  75 78 59 Erichsen flexibility, mm  4  4.4  3.2 Acetone double rubs  20  3030 Pencil hardness 2H 2H 2H Polyethylene adhesion  5  5  3 Waterresistance, 6 hrs.**  3  3  2 Conversion, % 100* 100* 90 *Double bondpeak intensity too low for quantitative measurement, below thesensitivity of the instrument. **Rank: 5 = No effect, 4 = Smallblisters, 3 = Easy to scracth, 2 = Very low scratch resist, 1 = Lifting,0 = Highly damaged

TABLE 2 Example 7 Example 8 Reference Pendulum hardness, König secs.  88 87  89 Erichsen flexibility, mm  3.9   4  3.4 Acetone double rubs400 >500 350 Curl, mm  2.3   1.9  2.3 Polyethylene adhesion  5   5  3Water resistance, 2 hrs.**  5   5  5 Water resistance, 24 hrs.**  2   4 2 Conversion, % 100*  100* N.a. *Double bond peak intensity too low forquantitative measurement, below the sensitivity of the instrument.**Rank: 5 = No effect, 4 = Small blisters, 3 = Easy to scracth, 2 = Verylow scratch resist, 1 = Lifting, 0 = Highly damaged N.a. = Notapplicable.

TABLE 3 Example 5 Example 5 5 pph 10 pph Reference Tensile Modulus 3.02.9 3.1 σYield, MPa 82.3 89.0 89.7 Strain, % 5.3 8.0 4.6 Critical StressIntensity Factor, 0.55 0.60 0.46 MPa · m^(1/2) Glasstransitiontemperature, ° C. 135 130 133

TABLE 4 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ref. Pendulum 18 10 10 46 3242 hardness - 24 hrs., König secs. Pendulum 20 10 10 55 42 48 hardness -2 days, König secs. Pendulum 24 10 10 57 45 52 hardness - 5 days, Königsecs.

Graph 1

Viscosity as a function of shear rate for product according to Example17.

1. A chain extended dendritic polyether comprising a dendritic corepolymer and a chain extension bonded to said dendritic core polymer,which chain extended dendritic polyether optionally is at leastpartially chain terminated or functionalised wherein said core polymeris a polyhydric dendritic polyether obtained by ring opening addition ofat least one oxetane to a di, tri or polyhydric core molecule at a molarratio yielding a polyhydric dendritic polyether comprising a coremolecule and at least one branching generation bonded to at least onehydroxyl group in said di, tri or polyhydric core molecule, and thatsaid chain extension is obtained by addition of at least one alkyleneoxide to at least one hydroxyl group in said core polymer at a molarratio of said core polymer to said alkylene oxide of between 1:1 and1:100.
 2. A chain extended dendritic polyether according to claim 1,wherein said alkylene oxide is ethylene oxide, propylene oxide,1,3-butylene oxide, 2,4-butylene oxide, cyclohexene oxide, butadienemonoxide, phenylethylene, oxide and mixture thereof.
 3. A chain extendeddendritic polyether according to claim 1 wherein said di, tri orpolyhydric core molecule is a 1,ω-diol, a 5-hydroxy-1,3-dioxane, a5-hydroxyalkyl-1,3-dioxane, a 5-alkyl-5-hydroxyalkyl-1,3-dioxane, a5,5-di(hyroxyalkyl)-1,3-dioxane, a 2-alkyl-1,3-propanediol, a2,2-dialkyl-1,3-propanediol, a 2-hydroxy-1,3-propanediol, a2-hydroxy-2-alkyl-]1,3-propanediol, a2-hydroxalkyl-2-alkyl-1,3-propanediol, a2,2-di(hydroxyalkyl)-1,3-propanediol or a dinner, trimer or polymer of asaid di, tri or polyhydric alcohol.
 4. A chain extended dendriticpolyether according to claim 1 wherein, said di, tri or polyhydric coremolecule is 1,4-butanediol, 1,5-pentanediol, 1.6-hexanediol,1,6-cyclohexanedimethanol, 5,5-dihydroxymethyl-1,3-dioxane,2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol,2-ethyl-2-butyl-1,3-propanediol, neopentyl glycol, dimethylolpropane,1,1-dimethylol-cyclohexane, glycerol, trimethylolethane,trimethylolpropane, diglycerol, ditrimethylolethane,ditrimethylolpropane, pentaerythritol, dipentaerythritol,anhydroennaehepitol, sorbitor or mannitol.
 5. A chain extended dendriticpolyether according to claim 1, wherein said di, tri or polyhydric coremolecule is a reaction product between at least one alkylene oxide and a1,ω-diol, a 5-hydroxy-1,3-dioxane, a 5-hydroxalkyl-1,3-dioxane, a5-alkyl-5-hydroxyalkyl-1,3-dioxane, a 5,5-di(hydroxy-alkyl)-1,3-dioxane,a 2-alkyl-1,3-propanediol, a 2,2-dialkyl-1,3-propanediol, a2-hydroxy-1,3-propanediol, a 2-hydroxy-2-alkyl-1,3-propanediol, a2-hydroxalkyl-2-alkyl-1,3-propanediol, a2,2-di(hydroxyalkyl)-1,3-propanediol or a dimer, trimer or polymer of asaid di, tri or polyhydric alcohol.
 6. A chain extended dendriticpolyether according to claim 1, wherein said di, tri or polyhydric coremolecule is a reaction product between at least one alkylene oxide and1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,6-cyclohexanedimethanol, 5,5-dihydroxmethyl-1,3-dioxane, 2-methyl-1,3-propanediol,2,-methyl-2-ethyl-1,3-propanediol, 2,-ethyl-2-butyl-1,3-propanediol,neopentyl glycol, dimethylolpropane, 1,1-dimethylolcyclohexane,glycerol, trimethylolethane, trimethylolpropane, diglycerol,ditrimethylolethane, ditrimethylolpropane, pentaerythritol,dipentaerythritol, anhydroenneahepitol, sorbitol or mannitol.
 7. A chainextended dendritic polyether according to claim 5, wherein said alkyleneoxide is ethylene oxide, propylene oxide, 1,3-butylene oxide,2,4-butylene oxide, cyclohexene oxide, butadiene monoxide and/orphenylethylene oxide.
 8. A chain extended dendritic polyether accordingto claim 1, wherein said oxetane is a 3-alkyl-3-(hydroxyalkyl)oxetane, a3,3-di(hydroxyalkyl)oxetane, a 3-alkyl-3-(hydroxalkoxy)oxetane, a3-alkyl-3-(hydroxy-alkoxyalkyl)oxetane or a dimer, trimer or polymer ofa 3-alkyl-3-(hydroxyalkyl)oxetane, a 3,3-di(hydroxyalkyl)oxetane, a3-alkyl-3-(hydroxyalkoxy)oxetane or a3-alkyl-3-(hydroxyalkoxyalkyl)oxetane.
 9. A chain extended dendriticpolyether according to claim 1, wherein said oxetane is3-methyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-(hydroxmethyl)oxetane or3,3-di(hydroxymethyl)oxetane.
 10. A chain extended dendritic polyetheraccording to claim 1, wherein said oxetane is an oxetane oftrimethylolethane, trimethylolporpane, pentaerythritol,ditrimethylolethane, ditrimethylolpropane or dipentaerythritol.
 11. Achain extended dendritic polyether according to claim 1, wherein saiddendritic polyehter is at least partially chain terminated by additionto said chain extension and/or said dendritic core polymer of at leastone aliphatic or aromatic saturated or unsaturated carboxylic acid or acorresponding anhydride or halide, aliphatic or aromatic mono ordiisocyanate, expoxidised saturated or unsaturated alcohol, allyl orvinylether, thiol, glycidyl ether, sulphonate or phosphate.
 12. A chainextended dendritic polyether according to claim 1, wherein saiddendritic polyether is at least partially chain terminated by additionto said chain extension and/or said dendritic core polymer of acrylicacid, methacrylic acid, crotonic acid, isocrotonic acid or a to saidacid corresponding anhydride or halide.
 13. A chain extended dendriticpolyether according to claim 1, wherein said dendritic polyether is atleast partially chain terminated by addition to said chain extensionand/or said dendritic core polymer of acetic acid, propionic acid,butyric acid, valeric acid, isobutyric acid, trimethylacetic acid,nonanoic acid, isononanoic acid, 2-ethyl-hexanoic acid, caproic acid,caprylic acid, capric acid, heptanoic acid, benzoic acid,para-tert.butylbenzoic acid, pelargonic acid, lauric acid, myristicacid, palmitic acid, stearic acid, isostearic acid, behenic acid,lignoceric acid, cerotic acid, montanoic acid, abietic acid, sorbinicacid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, erucicacid, soybean fatty acid, linseed fatty acid, dehydrated castor fattyacid, tall oil fatty acid tung oil fatty acid, sunflower fatty acid,safflower fatty acid, o-phthalic acid, isophtalic acid, terephtalicacid, azeleic acid, adipic acid and/or trimelletic acid or to a saidacid corresponding anhydride.
 14. A chain extended dendritic polyetheraccording to claim 1, wherein said dendritic polyether is at leastpartially functionalised by reaction with at least one selected from thegroup consisting of at least one allvi halide and at least oneepihalohydrin.
 15. A composition comprising a chain extended dendriticpolyether according to claim 1, wherein said composition comprises atleast 0.1% by weight of said dendritic polyether.
 16. A compositioncomprising a chain extended dendritic polyether according to claim 1,wherein said composition is selected from the group consisting of: i) anair dried alkyd resin, ii) a 1- or 2-component polyurethane coating oradhesive, iii) a saturated or unsaturated polyester, iv) a tougheningagent or thermosetting resins, v) a pigment dispersion agent forsolvent-free, solventbourne and waterborne coatings, vi) a waterdispersible resin for alkyd emulsions, acrylic dispersions polyurethanedispersions, vii) a dispersing polymer or resin, such as a reactivepolymeric surfactant, for non-amphifilic alkyds, polyesters, polyethersand polyurethanes, vii) a processing aid for polyolefines andthermoplastics, such as polycarbonates, polyamides, polyester,polyimides and polyurethanes, ix) a concrete admixture impartingfluidity to hydraulic compositions, such as cement pastes, mortars orconcretes, and x) a radiation curing coating, printing ink or adhesive.17. The chain extended dendritic polyether of claim 1, wherein the molarratio of said core polymer to said alkylene oxide is between 1:2 and1:50.
 18. The composition of claim 15, wherein said compositioncomprises 0.5–80% by weight of said dendritic polyether.
 19. Thecomposition of claim 15, wherein said composition comprises 0.5–50% byweight of said dendritic polyether.
 20. The composition of claim 15,wherein said composition comprises 1–25% y weight of said dendriticpolyether.
 21. A chain extended dendritic polyether according to claim14, wherein said at least one allyl halide is selected from the groupconsisting of allyl bromide and allyl chloride.
 22. A chain extendeddendritic polyether according to claim 14, wherein said at least oneepihalohydrin is selected from the group consisting of epichlorohydrinand epibromohydrin.
 23. The composition of claim 16, wherein saidtoughening agent is selected from the group consisting of an epoxyresins, unsaturated polyesters, vinyl esters, polyurethanes, maleimides,cyanate esters, phenolics, urea-formaldehyde resins andmelamine-formaldehyde resins, and/or composites made therefrom.